Combination vibrator and mixer



May 30, 1950 A. o. BRAATZ COMBINATION VIBRATOR AND MIXER Filed Feb. 8,1950 INVENTOR. IQRU-JUR O QQMTZ 85 Patented May 30, 1950 UNITED STATESPATENT OFFICE COMBINATION VIBRATOR AND MIXER Arthur 0. Braatz, Racine,Wis.

Application February 8, 1950, Serial N 0. 142,971

Claims. 1

This invention relates to improvements in a combination vibrator andmixer.

Dentists, jewelers, and others often find it necessary, in the course oftheir work to prepare relatively small quantities of plaster, silicates,or other investment materials. While mixing the ingredients for theplastic mass, a considerable amount of air is entrained in the form ofrelatively small bubbles. In order to produce a sound casting, it isnecessary to eliminate these bubbles before the mass is placed in amold, and it is important that all steps be performed quickly before theplastic material has had an opportunity to set.

It has been common practice in the past for dentists, in preparingplaster, to mix the ingredients by hand in a rubber cup or bowl. Afterthe plastic mass has been properly mixed, the cup and its contents havebeen vibrated'either by hand or by the use of a mechanical vibratingdevice. The vibrating devices heretofore placed on the market for thispurpose have been relatively expensive, and their high cost, consideredwith the fact that these devices are designed to perform a singleoperation only, has prevented these devices from coming into common use.Furthermore, these prior devices have imparted only a vertical up anddown movement to the cup.

With the above in mind, it is a general object of the present inventionto provide a combination mixing and vibrating device.

.A further object of the invention is to provide an improved device ofthe class described which is relatively inexpensive.

A further object of the invention is to provide a device of the classdescribed Which is adapted for convenient use in association with arubber cup or bowl of the type ordinarily used by dentists in mixingplaster ingredients.

A further object of the invention is toprovide a device of the classdescribed comprising an electric hand mixer having a pair of spacedrotatable shafts provided at their ends with mixing elements, saidshafts also being provided intermediate their length with eccentricvibrator portions.

A further object of the invention is to provide a device of the classdescribed whereinthe shaft portions between the mixing elements and themotor housing are long enough to permit the bottom of a mixing cup to beplaced on and vibrated by the eccentric members when the shafts aredisposed horizontally, so that the vibration may be performedimmediately after mixing.

A further object of the invention is to provide a device of the classdescribed which is strong and 2 durable, whichis'relatively simple inconstruction and easfly cleaned, and which is otherwise well adapted forthe "purposes described.

Withthe above and other objects in view, the invention consists of theimproved hand mixer, and all of its parts and combinations, as 'sctforthin 'theclaims, and all equivalents: thereof.

In "the drawing accompanying and forming-a part-oi this specification,wherein are showntwo embodiments of theinvention, and wherein likecharacters of reterenceinclicate the 'sameparts in all of the views:

Fig. 1 is aside elevational view of a preferred form of the improvedmixer showing it disposed in proper position to mix a quantity ofplastic material in a rubber cup of thetype commonly used by dentists, apart of said cup being broken away and shown in section;

Fig. 2 isan end view of themixer of 1 Premoved rrom the cup;

Fig. 3 is a side view of the preferred form of the improved mixershowing the shaftsthereo'f held in ahorizontal plenean'd showing therubber cup "and its plastic ingredients positioned ontl'ie eccentricportions of said shafts in a manner to be vibrated thereby when saidshafts are rotated;

Fig. '4 is a fragmentaryrside view of a modified form ofthe inventionwherein the eccentric portions of the shafts are formed by integral'offisets therein; and

5 is a sectional view taken approximately on the line 5-5 of Fig.'Bshowing the novel yibrating action.

Referring more particnlarlytoth'e drawing, the numeral I'O indicates anelectrically driven hand mixer of any suitable type having an elongatedbody ll of generally round cross-sectionalshape said body having builttherein an electric driving motor and suitable drive gearing as is wellknown in the art. A two-wire electrical conductor 12 projectsfrom oneend of the body I l and is provided with a suitable male plug (notshown) for connection with an electrical outlet. The operation of themixer id is controlled-cyan electrical switch I3 which is movableaxially of the body I to turn the motor on and on".

Projecting from the end portion of the body H which is opposite the endfrom which the conductor l2 projects, and disposedat substantially aright angle with respect to the longitudinal axis of the body I l, are apair of spaced parallel shafts N and I5. The shafts M and T5 are rotatedin opposite directions at the same speed. by the electric motor withinthe body ll through the before-mentioned conventional drive gearing 3(not shown). At the outer end of each of the shafts l4 and I5 is alooped mixing element I6. The element It on the shaft 14 is preferablypositioned at a right angle with respect to the element 16 of the shaftl5, and said elements are preferably of such size that they may besimultaneously accommodated in the conventional dentists plaster mixingcup 20.

Fixed to each of the shafts l4 and I5 in a position substantially midwayof the distance between the mixing elements IB and the body H is a cammember H. As shown in the drawing, each of the cam members II! has twodiametrically oppositely disposed high points, as indicated in Figs. 1to 3 by the numeral I8 which refers to the cam ll on the shaft l5 and bythe numerals 19 which refers to the cam on the shaft l4. Cams I! areangularly offset from one another as shown in Figs. 1 to 3, for apurpose which will be pointed out hereinafter.

In operation, the ingredients of a batch of plaster may be placed in arubber cup 2!], of the type commonly used by dentists, and saidingredients are then thoroughly mixed by introducing the mixing elementsis into said ingredients, as shown in Fig. 1, and. causing said mixingmembers to be rotated by the driving motor. The thorough mixingresulting from the use of the mixing elements I6 causes a considerableamount of air to be entrained in the plastic mass in the form ofbubbles, and said air must be eliminated before the mixture is used.

To remove the bubbles from the plastic mass in the cup 2i). the mixerit] may be immediately turned to the position shown in Fig. 3, and thecup 20 is preferably manually held with its bottom in contact with thecams H, as also shown in said figure. By causing the shafts I4 and I5,as well as the cams I! to be rotated while in the position of Fig. 3,the high points 18 and H! of the cams I! impinge upon the bottom of thecup 20 and cause said cup to be thoroughly vibrated. Since the cams I!are offset from one another and since the cams are rotating outwardly inreverse directions, the bottom of the cup on one side will be engagedfirst by one of the cams to tilt that side of the cup upwardly, and thecup in a somewhat tilted position will be moved upwardly andtransversely outwardly. The opposite side of the cup will then beengaged by one of the high points on the other cam to tilt the cup in areverse direction and move it upwardly and transversely outwardly in adirection opposite to its first direction of movement. This action isshown in Fig. 5. This vibration causes the air entrained in the plasticmass within the cup 20 to be rapidly expelled therefrom, and after theair is expelled by this method, the plastic mass is ready for use in theconventional manner.

It is an important feature of the invention that the shafts of id and i5be of sufiicient length that any conventional size cup 20 may beaccommodated by the improved device in the manner shown in Fig. 3.

Fig. 4 shows an alternative construction of the improved mixer whereinthe body is indicated by the numeral i, and the shafts are indicated bythe numerals l4 and I. In place of the cams H, the shafts l4 and I5 areformed with eccentric offsets [1 which serve the same purpose andoperate in substantially the same manner as the cams ll of the preferredform. It will :be noted that the offset ll of the shaft M is preferablydisplaced approximately 180 from the offset ll of the shaft [5.

It is apparent that the improved mixer provides, in a single device,means for mechanically mixing plastic materials as well as means forconveniently vibrating the plastic materials immediately after they havebeen thoroughly mixed. Thus, there is no substantial time intervalbetween mixing and vibrating and there is no chance for the mass toprematurely set. This inexpensive device eliminates the need forexpensive mixing or vibrating equipment, and it also reduces the amountof equipment necessary in an ofiice or laboratory while at the same timeincreasing the efficiency.

The improved device is simple in construction, compact, and easilycleaned,

Various changes and modifications may be made without departing from thespirit of the invention, and all of such changes are contemplated, asmay come within the scope of the claims.

What I claim is:

1. A combination vibrator and mixer, comprising: a body; at least onerotatable shaft projecting from said body; means in said body forrotating said shaft; a mixing element on said shaft adjacent theprojecting end thereof, said element being of such size that it may beaccommodated in a mixing cup, and said shaft having a portion ofsubstantial length between the body and said mixing element; and atleast one eccentric member on said shaft portion intermediate the mixingelement and said body, said eccentric member being adapted to serve as avibrator when a mixing cup is positioned in contact therewith duringrotation of the shaft.

2. A combination vibrator and mixer, comprising: a body; a pair ofspaced, parallel, rotatable shafts projecting from said body; means insaid body for rotating said shafts; a element on each of said shaftsadjacent the projecting end thereof, said elements being of such sizeand so positioned that they may be simultaneously accommodated in amixing cup, and said shafts each having ,a portion of substantial lengthbetween the body and said mixing elements; and an eccentric member fixedon each of said shaft portions intermediate the mixing element and saidbody, said eccentrics being adapted to serve as vibrators when a, mixingcup is positioned in contact therewith during rotation of the shaft.

3. A combination vibrator and mixer, comprising: a body; a pair ofspaced, parallel, rotatable shafts projecting from said body; means insaid body for rotating said shafts simultaneously at the same speed; amixing element on each of said shafts adjacent the projecting endthereof, said elements being of such size and so positioned that theymay be simultaneously accommodated in a mixing cup, and said shafts eachhaving a portion of substantial length between the body and said mixingelements; and an eccentric member fixed on each of said shaft portionsintermediate the mixing element and said body, the eccentric of oneshaft being angularly offset from the eccentric of the shaft, andeccentrics being adapted to serve as vibrators when a mixin cup ispositioned in contact therewith during rotation of the shaft.

4. A combination vibrator and mixer, comprising: a body; a pair ofspaced parallel rotatable shafts projecting from said body; means insaid body for rotating said shafts simultaneously at the same speeds; amixing element on each of said shafts adjacent the projecting endthereof, said elements being of such size and so positioned that theymay be simultaneously accommodated in a mixing cup, and said shafts eachhaving a portion of substantial length between the body and said mixingelements; and an eccentric member fixed on each of said shaft portionsintermediate the mixing element and said body, said eccentric memberseach having a pair of diametrically oppositely disposed offset portions,and the eccentric member of one shaft bein angularly offset from theeccentric member of the other shaft, and said eccentrics being adaptedto serve as vibrators when a mixing cup is positioned in contacttherewith during rotation of the shaft.

5. A combination vibrator and mixer, comprising: a body; a pair ofspaced parallel rotatable shafts projecting from said body; means insaid body for rotating said shafts simultaneously at the same speed; amixing element on each of said shafts adjacent the projecting endthereof, said elements being of such size and so positioned that theymay be simultaneously accommodated in a mixing cup, and said shafts eachhaving a portion of substantial length between the body and said mixingelements; and an eccentric offset formed in each of said shaft portionsintermediate the mixing element and said body, the eccentric offset inone shaft being angularly disposed with respect to the offset in theother shaft, and said offsets being adapted to serve as vibrators when amixing cup is positioned in contact therewith during rotation of theshaft.

ARTHUR O. BRAATZ.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,839,082 Burgard Dec. 29, 19311,863,977 Forde et a1 June 21, 1932 2,048,756 Shultz July 28, 19362,293,959 Wright Aug. 25, 1942 2,483,727 Frisbie Oct. 4, 1949 FOREIGNPATENTS Number Country Date 9,253 Australia Sept. 28, 1933

